Calculate the recommended wire size based on device type, power or current, and cable length.
This 12V cable size calculator helps estimate the suitable wire size to reduce voltage drop and improve the performance of electrical devices in cars, camping setups, and overland builds. Enter the device power or current, then the one-way cable length, and the calculator will estimate the recommended wire size in mm², the approximate AWG equivalent, and a suggested fuse size.
No. Enter the one-way cable length from the battery to the device only. The calculator internally accounts for the full circuit length.
No. This version is designed for 12V systems only. A 24V system requires a different calculation.
The suggested fuse size is an estimate. If the device manufacturer recommends a specific fuse size, follow the manufacturer’s recommendation.
The calculation is based on copper resistance. Low-quality or CCA cables may cause more heat and voltage drop even if the printed size looks correct.
The AWG value is approximate for comparison. The main reference in this calculator is the mm² size.
This calculator is an estimation tool for choosing a suitable wire size for 12V DC systems. It is not a replacement for professional inspection or manufacturer instructions. Results depend on the values entered by the user and assume the use of real copper cable from a trusted source. Actual requirements may vary depending on cable quality, installation method, temperature, terminal crimping, real cable routing, and load type.
